On Fri, Jul 18, 2008 at 10:05 AM, Gurjeet Singh <[EMAIL PROTECTED]> wrote:
> On Fri, Jul 18, 2008 at 9:58 AM, Tom Lane <[EMAIL PROTECTED]> wrote: > >> "Gurjeet Singh" <[EMAIL PROTECTED]> writes: >> > During these spikes, in the 'top' sessions we see the 'idle' PG >> > processes consuming between 2 and 5 % CPU, and since the box has 8 CPUS >> (2 >> > sockets and each CPU is a quad core Intel Xeon processors) and somewhere >> > around 200 Postgres processes, the load spikes to above 200; and it does >> > this very sharply. >> >> This looks like heavy contention for a spinlock. You need to get a >> higher-level analysis of what's happening before anyone can say much >> more than that. >> >> Note that 8.1 is pretty much ancient history as far as scalability to >> 8-core hardware goes. You should probably consider updating to 8.3 >> before investing too much time in tracking down what's happening. >> If you can still show the problem on 8.3 then there would be some >> interest in fixing it ... > > > Upgrading is on the cards, but not as high priority as I would like it to > be! This is a production box, and we desperatly need some respite from these > spikes. > > Can you please elaborate on what high level diagnosis would you need? > > I just ran DROP SCHEMA _<slony schema> CASCADE; and it spiked again, on a > very low loaded box!! > > Thanks for all you help. > Would reducing the number of connections on the DB help in reducing the spike? -- [EMAIL PROTECTED] [EMAIL PROTECTED] gmail | hotmail | indiatimes | yahoo }.com EnterpriseDB http://www.enterprisedb.com Mail sent from my BlackLaptop device
